This research project is aimed at the elucidation of the hydrophobic interaction between simple apolar species dissolved in water. During the preceding year we have been able to construct a novel Monte Carlo scheme in which the standard Metropolis technique is wed to energy minimization techniques. This code is rapidly convergent and during the next year will be applied to the hydrophobic interaction. In addition this method will be used to resolve the recent argument by others that the standard Monte Carlo and molecular dynamics methods are in disagreement for water. During the preceding year we have observed a layering phenomenon in polystyrene solutions, and have attributed this to a spinodal decomposition. During the last year of this grant, we will study the dynamics of these heterogeneous samples using laser light scattering.